Title :
Laser-ultrasonics three-dimensional imaging of advanced composite materials
Author :
Aussel, J.-D. ; Choquet, M. ; Canas, R. ; Bouchard, P. ; Padioleau, C. ; Héon, R.
fDate :
Oct. 31 1994-Nov. 3 1994
Abstract :
We present a laser-ultrasonic system that can scan large areas of parts made from composite materials. Since, with laser-ultrasonics, there is no need for normal incidence of the laser beams on the part to be inspected, this system can inspect samples of curved or awkward surfaces using a two rotation-axis scanning mirror. A ranging system accurately measures the distance of the part from the system. The angular position of the scanning mirror and the range information provide a spherical reconstruction model that allows us to generate (without prior knowledge) the geometry of the surface of the inspected part. Since the laser generated ultrasonic pulses propagate in a direction normal to the surface, the reconstruction model includes the generation of a mesh of the surface to determine the normal direction. With traditional tools for three dimensional representation, such as voxelization and isosurfaces, we obtain a powerful method for visualizing the inspection of composite materials of complex shapes
Keywords :
acoustic pulses; composite materials; image reconstruction; inspection; laser ranging; photoacoustic effect; surface topography measurement; ultrasonic imaging; ultrasonic materials testing; C-scans; advanced composite materials; awkward surfaces; curved surfaces; graphite-epoxy composite; inspection visualization; isosurfaces; laser generated ultrasonic pulse propagation; laser optical triangulation; laser-ultrasonics three-dimensional imaging; ranging system; reconstruction model; spherical reconstruction model; surface geometry; surface mesh generation; three dimensional representation; two rotation-axis scanning mirror; voxelization; Acoustic imaging/mapping; Acoustic pulses; Acoustic testing; Image reconstruction; Inspection; Nondestructive testing; Nonhomogeneous media; Optical distance measurement; Photoacoustic materials/effects;
Conference_Titel :
Ultrasonics Symposium, 1994. Proceedings., 1994 IEEE
Conference_Location :
Cannes, France
Print_ISBN :
0-7803-2012-3
DOI :
10.1109/ULTSYM.1994.401823